/Engine/Source/Runtime/Engine/Public/AnimationRuntime.h
Create Mask Weight for skeleton joints, not per mesh or per required bones You'll have to filter properly with correct mesh joint or required bones The depth should not change based on LOD or mesh or skeleton They still should contain same depth
static void CreateMaskWeights ( [TArray](API\Runtime\Core\Containers\TArray)< [FPerBoneBlendWeight](API\Runtime\Engine\Animation\FPerBoneBlendWeight) > & BoneBlendWeights, const [TArray](API\Runtime\Core\Containers\TArray)< [FInputBlendPose](API\Runtime\Engine\Animation\AnimData\FInputBlendPose) > & BlendFilters, const [USkeleton](API\Runtime\Engine\Animation\USkeleton) * Skeleton )